US President Joe Biden has told Congress his Russian counterpart Vladimir Putin misjudged how the West would hit back when he invaded Ukraine.
In a primetime speech, Mr Biden vowed “an unwavering resolve that freedom will always triumph over tyranny”.
His State of the Union speech comes as pandemic-weary Americans grapple with galloping inflation.
Mr Biden is almost as unpopular as Donald Trump at this point in his presidency.
The Democratic president told lawmakers on Tuesday night: “Putin’s war was premeditated and unprovoked. He rejected repeated efforts at diplomacy.
“He thought the West and Nato wouldn’t respond. And, he thought he could divide us here at home.
“Putin was wrong. We were ready.”
Mr Biden announced that the US would ban Russian aircraft from American airspace, following similar bans by Canadian and European authorities.
Vowing further economic retaliation against Russia, the US president said of Mr Putin: “He has no idea what’s coming.”
The US president also welcomed Ukrainian Ambassador Oksana Markarova, who was sitting in US First Lady Jill Biden’s VIP box for the event.
Mr Biden’s State of the Union speech, an annual event pushing a president’s agenda, comes as his personal popularity languishes in the doldrums.
Just 40.6% of Americans approve of the job he is doing, according to the RealClearPolitics polling average. Although the US jobless rate has sunk to 4%, inflation has hit a 40-year high.
The nation’s homicide rate has spiked to a 25-year high.
Opinion polls have shown Americans unhappy with Mr Biden’s handling of the coronavirus pandemic and the chaotic US withdrawal from Afghanistan last year.
The president sought on Tuesday night to empathise with hard-pressed working families, saying: “Inflation is robbing them [Americans] of gains they thought otherwise they would be able to feel. I get it.”
He promised a plan for “building a better America”.
Mr Biden argued the best way to counter soaring consumer prices was to boost domestic production of cars and semiconductors and rebuild the nation’s roads and bridges.
But his biggest foreign policy crisis, the invasion of Ukraine, dominated the opening of his speech.
Hours before his address, Mr Biden spoke to Ukrainian President Volodymyr Zelensky to discuss what US help he could give his country after six days of the Russian assault.